Loop-takers for sewing machines



Oct. 28, 1958 c. R. ODERMANN 2,8 6

Y LOOP-TAKERS FOR smwmc: MACHINES Filed June 14, 1955 63 Qsgugnuuk Fig. 3

v INVENTOR W'TNESS Charles R. Odermonn 6?) 3' AT ORNEY United States Patent LOOP-TAKERS FOR SEWING MACHINES Charles R. Odermann, Milford, Conn., assignor to The Singer Manufacturing Company, Elizabeth, N. L, a corporation of New Jersey Application June 14, 1955, Serial No. 515,485

1 Claim. (Cl. 112-228) This invention relates to lock-stitch sewing machines and more particularly to an improved circularly moving loop-taker especially adapted for use with'lock-stitch sewing machines.

Loop-takers, of the type referred to herein, have been used for many years, and generally comprise a cupshaped body secured to the end of a rotary shaft, a thread-case carrier, a thread-case, and a bobbin or other form of thread carrier housed in the thread-case. The thread-case carrier, which is received in the cup-shaped body, is restrained from rotating with the cup-shaped body by means of a restraining finger or other member fixed to the bed of the sewing machine. In order to accommodate the relative rotary movement between the cup-shaped body and the thread-case carrier, the inner surface of the cylindrical side-wall of the cup-shaped body is provided with a circular raceway and the outer cylindrical surface of the thread-base carrier is formed with a peripheral bearing rib which is received in the above mentioned raceway. In the past it has been customary to hold the peripheral rib formed on the thread-case carrier in the circular raceway by means of one or more metallic gibs. In some instances the metallic gib has been formed integral with the cup-shaped body (see U. S. Patent No. 2,101,320) and in other cases the metallic gib has. been formed separatelyand then secured to the cup-shaped body by a plurality of screws (see U. S. Patent application Serial No. 370,407, filed July 27, 1953, now Patent No. 2,716,956).

While loop-takers heretofore used have, for the most part, been quite satisfactory, some difliculty has developed in that the mouth of the raceway which receives the discontinuous rib of the thread-case carrier has in some cases become so badly chipped that it was necessary to replace the loop-taker. Many attempts have been made to rectify this situation, but none of these attempts has provided the complete answer to the problem of chipped raceways.

In the loop-taker of the present invention the gib which holds the thread-case carrier rib in the raceway is nonmetallic and preferably is formed of a synthetic plastic such as nylon, the gib being held in place by a plurality of screws. Experience has shown that the use of a nonmetallic gib of the type herein disclosed provides a resilience to the rotary hook which practically eliminates the aforementioned chipping. Therefore, the primary object of the present invention is to provide an improved loop-taker provided with a nonmetallic synthetic plastic nylon gib.

Another object of the invention is to provide 'an improved loop-taker having a nonmetallic gib which practically eliminates chipping of the raceway.

In the accompanying drawings:

Fig. l is a plan view of a complete loop-taker embodying the present invention;

2,857,869 Patented Oct. 28, 1958 Fig. 2 is a plan view of the cup-shaped body which forms a part of the loop-taker shown in Fig. 1;

Fig. 3 is a sectional view taken along the line 3-3 of Fig. 2; and

Fig. 4 is a perspective view of the removable nonmetallic nylon gib.

Referring to the drawings, the invention has been shown in Figs. 1 to 4 as embodied in a loop-taker adapted for use with a lock-stitch sewing machine and comprising a cup-shaped body 11, a thread-case carrier 12 and a thread-case 13; it being understood that a bobbin or other form of thread supply (not shown) is housed in the thread-case.

The cup-shaped body 11 has a cylindrical hub 14 which, by means of screws (not shown) carried in threaded holes 16, is secured to one terminal end of a rotary shaft (not shown). The cup-shaped body 11 has a bottom wall consisting of a pair of radial arms 17 extending from one end of the hub 14 thereby supporting a cylindrical side wall 18 having a number of well known elements such as an integral. loop-seizing beak 19, an upstanding wall 20, an overhanging part 21 and a circular raceway 22, the raceway having a base 23 and a side wall 24. A separately formed. substantially semicylindrical needle-guard 26 is held to the side of the cylindrical side wall 18 by means of a pair of horizontally extending screws (not shown). A peripheral bearing rib 33 is formed on the outer cylindrical surface of the thread-case carrier 12 and this rib 33 is journaled in the raceway 22, a hereinafter described gib 34 acting to hold the bearing rib 33 in the raceway 22. In accordance with well-known practice, the thread-case carrier 12 and the thread-case 13 are held stationary during the sewing operation by means of a finger 36 formed on the thread-case carrier 12 and this finger engages a stationary restraining member (not shown) supported from the bed of the sewing machine. In other words, the cup-shaped body 11 rotates around the stationary thread-case 12 and the thread-case 13.

The gib 34 which is made of a nonmetallic material, such as a synthetic plastic, preferably nylon, is of uniform axial thickness and, except for a gap 59, is substantially annular in form and is divided at an offset 60 into two portions of different radial width. The wide portion 61 is beveled on both sides, as at 62 and 62, and is provided with two countersunk holes 63 adapted to receive screws 64 by which the gib 34 is secured to the cup-shaped body 11. The narrow portion 66 is beveled on its inner side, as at 62, and has an outer face 68 which is in the form of a portion of a cylinder. The end of the portion 66 is pointed, as at 69.

Since the gib 34 is made of a nonmetallic material, viz. a synthetic material commonly known as nylon, the gib 34 provides a very satisfactory bearing surface for the rib 33. Also the nylon of the gib 34 is yieldable and, therefore, the use of the nylon gib provides the loop-taker with a yieldable raceway, an attribute much desired in loop-takers. Furthermore, the use of a nonmetallic gib provides an inexpensive and satisfactory way of preventing chipping of the raceway of a rotary hook.

Having thus set forth the nature of the invention, what I claim herein is:

A loop-taker for lock-stitch sewing machines comprising a metallic thread-case carrier having a metallic discontinuous peripheral bearing rib; a metallic cupshaped body adapted to receive said thread-case carrier; a metallic side wall formed as part of said cup-shaped body and having an inner surface with a circular raceway adapted rotatably to receive said discontinuous A t; 1. metallic rib, said circular, raceway having a mouth which rotates with respect to said stationarily held discontinuous receives the leading end of said discontinuous metallic metallic rib. rib each time said cup-shaped body rotates; and a detachable nylon gib secured to said metallic cup-shaped body References Cited in the file of this Patellt and having a nylon portion overlying said discontinuous 5 UNITED STATES PATENTS metallic rib when said thread-case carrier is in position in said cup-shaped body, said nylon gib providing a reslience to said loop-taker which prevents chipping of the mouthof said raceway when said cup-shaped body 2,548,815 Petskeyes Apr. 10, 1951 2,673,541 Bieserneyer Mar. 30, 1954 

